% mod_tex: distributed LaTeX-rendering over Apache % Copyright (C) 2007 Peter Danenberg % See doc/COPYING for details. \documentclass[12pt]{article} \usepackage{amsmath,stmaryrd,amssymb} \usepackage{cancel} \usepackage{color} \pagestyle{empty} \begin{document} \begin{displaymath}\end{displaymath} \(A=\begin{bmatrix} \cos{\alpha}&\sin{\alpha}\\ -\sin{\alpha}&\cos{\alpha} \end{bmatrix}\); prove \(A^T=A^{-1}\) (\emph{id est}, that A is orthogonal). \begin{displaymath}\end{displaymath} \end{document}